The treatment of deep wounds historically involved salves, solutions or solid medicament carriers in impregnated wound coverings. These treatments at best were ineffective and often due to the toxic secretions emanating deep in the wound resulted in further tissue damage or injurious reactions and infections.
Vacuum bandages over a wound were disclosed in German patent DE 4012232 A1 wherein the wound is covered by a thin semi-permeable foil. A supply line and a removal line are provided under the foil in the wound area. Active substances can be applied to the wound surface under the foil via the supply line by means of a syringe. After the desired application period the active substances can, in certain cases together with the wound secretion, be suctioned out via the removal line by means of a vacuum source. The supply line is provided with a self-acting closing safety valve, which is opened by the introduced syringe for introduction of the fluid active substances. Likewise there is provided on the removal line a closure or blockage mechanism, which closes off the output side during the application period of the active substance.
In this known installation bandage the active substances are applied directly upon the wound surface and suctioned off from the wound surface. The active substance can thus only be applied in imprecise doses and in particular in the case of large wound surface areas an even effect upon the entire surface is difficult to achieve. A long time continuous effect can not realized.
From U.S. Pat. No. 4,382,441 it is known, for treatment of wound surfaces, to lay a padding or dressing made of a porous material upon the wound surface and to sealingly cover this. The active substance to be applied is continuously conveyed through the padding, for which a fluid supply connection and a fluid removal connection communicate with the padding. The capillary effect of the porous padding optimizes the distribution of the supplied active substance over the entirety of the surface of the padding in contact with the wound surface.
The porous padding is substantially form-stable and also the sealing cover is preferably form-stable. The fluid active substance is conveyed through the padding in a continuous stream, whereby a stream distribution results, in which the fluid active substance flows essentially along the area between the fluid supply connection and fluid removal connection, while the edge areas of the padding are barely perfused. Thus, in these edge areas the active substances are only exchanged in small amounts and, further, in the edge areas accumulations of wound secretion are only insufficiently removed. Beyond this the relatively form stable padding does not lie in all areas equally against the wound surface, so that also hereby an even application of the active substance and an even removal of the wound secretion is compromised. A continuous effect is not envisioned or intended.
A solution to the above mentioned deficiencies in deep wound treatments was proposed in US patent application 2007/0021698 A1, the summary of which is repeated as follows. The invention was concerned with the task, of providing a process and device for application of active substances to a wound surface, which guarantees a high effectiveness of the applied active substance over the entire wound surface, makes possible an optimal dosing of the active substance, and enhances the wound healing process.
The basic idea of the invention was to lay a padding or bandage of an elastic compressible porous material upon the wound surface and to cover the wound surface and the padding with a sealing layer or foil, which closes off the wound and the padding against the atmosphere. The supply line and the removal line are respectively provided with controllable closure devices which at the appropriate time are so controlled, that the introduction of the active substance and the suctioning off of the active substance and in certain cases the wound secretion are separated from each other in time. Between the time interval in which the closure device of the supply line is opened and the active substance is supplied, and the point in time, in which the closure device of the removal line is opened in order to suction out the active substance and the wound secretion, there is programmed or provided an treatment dwell time interval, in which both closure devices are closed and the active substance statically has an effect upon the wound surface. After the suctioning off of the active substance and the wound secretion there was, besides this, a time interval programmed in which the closure mechanism of the supply side remains closed and a vacuum is maintained in the area of the wound. For this the closure mechanism of the suctioning side can remain open, so that via the vacuum source a constant vacuum is maintained in area of the wound and the wound secretion is suctioned off. The closure mechanism of the removal side can also be closed, so that the vacuum produced initially can be maintained. It is also possible in this phase that the closure mechanism of the removal side is temporarily controlled to be open, in order that the vacuum is reestablished, in case this drops below a pre-determined value.
The dwell time interval, in which the padding is impregnated or soaked with the active substance and the active substance was applied with a continuous effect upon the wound surface, was selected corresponding to the nature of the active substance, its dosing and the indications given by the condition of the wound surface. In the vacuum time interval, in which no active substance is applied and only the wound secretion is suctioned off, the bodily immunological repair and immune processes of the tissue can proceed unhindered, so that the wound healing is optimized. Thus, active treatment phases and healing phases alternate temporally one after the another. In the treatment phase the wound system is actively engaged by means of the active substances, such as for example antibiotics or antiseptics, in order to fight or combat infections and the like. Since such active substances as a rule besides the desired main effect also have undesired side effects, the active substances are suctioned off subsequent to the active treatment phase and with them the wound secretion, which contains the decomposition products produced during the active treatment phase with their, in certain cases, toxic agents. In the subsequent vacuum time interval the body's own immunological healing process can proceed optimally, without being compromised by the undesired side effects of the active substances and the decomposition products produced during the combating of the wound infection.
Preferably the closure mechanisms of the supply line and removal line are temporally so controlled, that the introduction of the active substance begins slowly and with a minimal volumetric stream. Thereby it is prevented, that wound pain is caused or increased by a too-sudden and rapid introduction of active substance. Likewise, the opening of the closure mechanism of the removal line is temporally controlled in such a manner, that the vacuum increases only gradually. A too rapid, sudden vacuum leads likewise to substantially wound pain.
The padding provided upon the wound surface is comprised of an elastic compressible porous material, preferably a PVA-sponge (polyvinyl alcohol-sponge), wherein a flexible foil is employed for covering. If a vacuum is produced in the foil-covered wound area, then the foil lies tightly upon the wound and compresses the padding. Thereby the padding lies over its entire surface equally tightly on the wound surface. This improves the suctioning off of the wound secretion during the vacuum time interval. Should the inlet opening be opened for introduction of the active substance, then the porous padding suctions the active substance in, whereby it expands on the basis of its elastic resilience. Thereby it is achieved, that the padding evenly absorbs the active substance in the manner of a sponge. The active substance is evenly distributed over the entire surface of the padding and acts upon the entire wound surface in an even manner. This is improved thereby, that the padding in the vacuum phase lies tightly against the wound surface. The even distribution of the active substance over the entire surface is not impeded or hindered during the active treatment phase, since after the end of the introduction, during the active treatment time interval, a static condition exists, in which the introduction and removal lines are closed.
Since the wound treatment can extend over a longer period of time, for example over several days, it can occur, that in particular during a longer vacuum phase the pores of the padding slightly adhere or become glued together. Such adhesion increases the resistance against the introduction of active substance. Thereby the introduction of the active substance by gravity can be impeded. In such a case it is purposeful, at the beginning of the introduction of the active substance, to first rinse the porous padding clean. For this, at the beginning of the introduction of the active substance, first a small volume of a fluid active substance is introduced under pressure, in order to rinse through the pores of the padding and to dissolve adhered areas. The introduction under pressure can advantageously be achieved by a syringe, which is connected to the inlet. Via piston pressure of the syringe a first dose of active substance can be employed for rinsing under pressure, before the introduction of the active substance occurs by gravity. In certain cases it is also possible, that the amount of the fluid active substance necessary for the entire introduction period is supplied by means of the syringe.
The process and vacuum wound covering device as described therein US application 2007/0021689 is incorporated herein by reference in its entirety. The use of this form of device provides a unique and heretofore unused opportunity for more rapidly initiating the healing process in such difficult large and deep wounds.
Historically vacuum bandages employed a sponge which by its cellular open pore nature exhibited numerous air pockets.
Applicants of the present invention have developed a new family of unfocused or wide area unfocused acoustic shock waves that can transmit wave patterns with either a wide area focal region or with no focal point or a focal point lying outside the wound area, preferably external of the patient's body. The acoustic wave patterns provide both a germicidal effect on the tissue upon which they impinge, and also are known to accelerate healing. These wave patterns are best transmitted through a fluid gel to the applicator head and the patient's skin directly. With covered wounds as described above, transmission through the bandage was considered impossible due to the residual air pockets and therefore the use of such shock waves was not contemplated as complimentary to vacuum wound treatments.
A subtle heretofore unappreciated, but remarkably simple adjustment of the use of such vacuum bandage devices as described in the prior art provides the basis for the present invention.